Abstract: In an impactor, e.g. a jack hammer, a liquid column is accelerated through an empty barrel 26 and it impacts on a piston surface (34) of the tool (24), e.g. a chisel.

Abstract: A hard compact material, such as rock, is broken by forcing a longish mass body of relatively incompressible fluid, such as water, against the material to be broken. The mass body is caused to impact the material at a momentum necessary for breaking the material. The momentum is generated by supplying the fluid to a storage chamber against the effect of a thrust load acting upon the fluid in the storage chamber. When a sufficient amount of fluid has been supplied the fluid in the storage chamber is forced toward the material to be broken by the effect of the thrust load.

Abstract: A hard compact material, such as rock, is broken by driving a longish mass body of relatively incompressible fluid, such as water, against the material to be broken. The mass body is caused to impact the material at a momentum required for breaking the material. The required momentum is obtained by adding the momentum of at least two fluid mass bodies. The longish mass body can be aligned with a drill hole by means of the drill bit and rod. The energy generator or fluid gun and the gun barrel can be made in separable units.

Abstract: A hard compact material, such as rock, is broken by forcing an elongated mass body of relatively incompressible fluid, such as water, against the material to be broken. The mass body is caused to impact the material at a momentum necessary for breaking the material. The momentum is generated by supplying the fluid to a storage chamber against the effect of a thrust load acting upon the fluid in the storage chamber. When a sufficient amount of fluid has been supplied the fluid in the storage chamber is forced toward the material to be broken by the effect of the thrust load.

Abstract: A hard compact material, such as rock, is broken by maintaining a column of relatively incompressible fluid, such as water, extending from outside into at least one hole which has been pre-drilled in the material to be broken. A shock wave is generated in the column outside the hole and is transmitted through the column into the hole. Due to the energy of the propagated shock wave, cracks are initiated and driven to a free surface of the material to break same. Breakage by the effect of the shock wave may be facilitated by means of an explosive. The explosive is delivered into the hole prior to the admission of fluid thereinto and is initiated by means of the transmitted shock wave.

Abstract: A hard compact material, such as rock, is broken by directing a high velocity jet of fluid, such as water, into a drill hole in the material to be broken. The jet is generated by a nozzle and is directed into the drill hole through a tubular member, which is associated with the nozzle. Upon having traversed the tubular member, the jet is suddenly arrested in the hole to break the material by the established jet stagnation pressure stemmed by the tubular member.

Abstract: A hard compact material, such as rock, is broken by forcing a longish mass body of relatively incompressible fluid, such as water, against the material to be broken. The mass body is directed into a hole in the material for impacting a surface therein. Prior to the impact delivering the mass body is accelerated to an impact velocity of sufficient magnitude for causing cracks to form in the material. Further, cracks in the hole are propagated toward a free surface in the material by the effect of the momentum or kinetic energy of the mass body.

Abstract: A hard compact material, such as rock, is broken by delivering an explosive into at least one hole which has been pre-drilled in the material to be broken and by forcing a relatively incompressible fluid, such as water, into the hole to impact the explosive to initiate same. Upon detonation of the explosive the fluid stems the hole thereby delaying leakage of blasting gases out of the hole before the material is broken. Preferably, the explosive and the fluid are launched together into the hole. In this case may the explosive and the fluid be encapsulated in a common cover.